1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 //! Provides keys to LDK and defines some useful objects describing spendable on-chain outputs.
12 //! The provided output descriptors follow a custom LDK data format and are currently not fully
13 //! compatible with Bitcoin Core output descriptors.
15 use bitcoin::blockdata::transaction::{Transaction, TxOut, TxIn, EcdsaSighashType};
16 use bitcoin::blockdata::script::{Script, Builder};
17 use bitcoin::blockdata::opcodes;
18 use bitcoin::network::constants::Network;
19 use bitcoin::util::bip32::{ExtendedPrivKey, ExtendedPubKey, ChildNumber};
20 use bitcoin::util::sighash;
22 use bitcoin::bech32::u5;
23 use bitcoin::hashes::{Hash, HashEngine};
24 use bitcoin::hashes::sha256::HashEngine as Sha256State;
25 use bitcoin::hashes::sha256::Hash as Sha256;
26 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
27 use bitcoin::hash_types::WPubkeyHash;
29 use bitcoin::secp256k1::{SecretKey, PublicKey, Scalar};
30 use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature, Signing};
31 use bitcoin::secp256k1::ecdh::SharedSecret;
32 use bitcoin::secp256k1::ecdsa::RecoverableSignature;
33 use bitcoin::{PackedLockTime, secp256k1, Sequence, Witness};
35 use crate::util::transaction_utils;
36 use crate::util::crypto::{hkdf_extract_expand_twice, sign};
37 use crate::util::ser::{Writeable, Writer, Readable};
39 use crate::util::events::HTLCDescriptor;
40 use crate::chain::transaction::OutPoint;
41 use crate::ln::channel::ANCHOR_OUTPUT_VALUE_SATOSHI;
42 use crate::ln::{chan_utils, PaymentPreimage};
43 use crate::ln::chan_utils::{HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, HolderCommitmentTransaction, ChannelTransactionParameters, CommitmentTransaction, ClosingTransaction};
44 use crate::ln::msgs::{UnsignedChannelAnnouncement, UnsignedGossipMessage};
45 use crate::ln::script::ShutdownScript;
47 use crate::prelude::*;
48 use core::convert::TryInto;
49 use core::sync::atomic::{AtomicUsize, Ordering};
50 use crate::io::{self, Error};
51 use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
52 use crate::util::invoice::construct_invoice_preimage;
54 /// Used as initial key material, to be expanded into multiple secret keys (but not to be used
55 /// directly). This is used within LDK to encrypt/decrypt inbound payment data.
57 /// (C-not exported) as we just use `[u8; 32]` directly
58 #[derive(Hash, Copy, Clone, PartialEq, Eq, Debug)]
59 pub struct KeyMaterial(pub [u8; 32]);
61 /// Information about a spendable output to a P2WSH script.
63 /// See [`SpendableOutputDescriptor::DelayedPaymentOutput`] for more details on how to spend this.
64 #[derive(Clone, Debug, PartialEq, Eq)]
65 pub struct DelayedPaymentOutputDescriptor {
66 /// The outpoint which is spendable.
67 pub outpoint: OutPoint,
68 /// Per commitment point to derive the delayed payment key by key holder.
69 pub per_commitment_point: PublicKey,
70 /// The `nSequence` value which must be set in the spending input to satisfy the `OP_CSV` in
71 /// the witness_script.
72 pub to_self_delay: u16,
73 /// The output which is referenced by the given outpoint.
75 /// The revocation point specific to the commitment transaction which was broadcast. Used to
76 /// derive the witnessScript for this output.
77 pub revocation_pubkey: PublicKey,
78 /// Arbitrary identification information returned by a call to [`ChannelSigner::channel_keys_id`].
79 /// This may be useful in re-deriving keys used in the channel to spend the output.
80 pub channel_keys_id: [u8; 32],
81 /// The value of the channel which this output originated from, possibly indirectly.
82 pub channel_value_satoshis: u64,
84 impl DelayedPaymentOutputDescriptor {
85 /// The maximum length a well-formed witness spending one of these should have.
86 // Calculated as 1 byte length + 73 byte signature, 1 byte empty vec push, 1 byte length plus
87 // redeemscript push length.
88 pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 1 + chan_utils::REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH + 1;
91 impl_writeable_tlv_based!(DelayedPaymentOutputDescriptor, {
92 (0, outpoint, required),
93 (2, per_commitment_point, required),
94 (4, to_self_delay, required),
95 (6, output, required),
96 (8, revocation_pubkey, required),
97 (10, channel_keys_id, required),
98 (12, channel_value_satoshis, required),
101 /// Information about a spendable output to our "payment key".
103 /// See [`SpendableOutputDescriptor::StaticPaymentOutput`] for more details on how to spend this.
104 #[derive(Clone, Debug, PartialEq, Eq)]
105 pub struct StaticPaymentOutputDescriptor {
106 /// The outpoint which is spendable.
107 pub outpoint: OutPoint,
108 /// The output which is referenced by the given outpoint.
110 /// Arbitrary identification information returned by a call to [`ChannelSigner::channel_keys_id`].
111 /// This may be useful in re-deriving keys used in the channel to spend the output.
112 pub channel_keys_id: [u8; 32],
113 /// The value of the channel which this transactions spends.
114 pub channel_value_satoshis: u64,
116 impl StaticPaymentOutputDescriptor {
117 /// The maximum length a well-formed witness spending one of these should have.
118 // Calculated as 1 byte legnth + 73 byte signature, 1 byte empty vec push, 1 byte length plus
119 // redeemscript push length.
120 pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 34;
122 impl_writeable_tlv_based!(StaticPaymentOutputDescriptor, {
123 (0, outpoint, required),
124 (2, output, required),
125 (4, channel_keys_id, required),
126 (6, channel_value_satoshis, required),
129 /// Describes the necessary information to spend a spendable output.
131 /// When on-chain outputs are created by LDK (which our counterparty is not able to claim at any
132 /// point in the future) a [`SpendableOutputs`] event is generated which you must track and be able
133 /// to spend on-chain. The information needed to do this is provided in this enum, including the
134 /// outpoint describing which `txid` and output `index` is available, the full output which exists
135 /// at that `txid`/`index`, and any keys or other information required to sign.
137 /// [`SpendableOutputs`]: crate::util::events::Event::SpendableOutputs
138 #[derive(Clone, Debug, PartialEq, Eq)]
139 pub enum SpendableOutputDescriptor {
140 /// An output to a script which was provided via [`SignerProvider`] directly, either from
141 /// [`get_destination_script`] or [`get_shutdown_scriptpubkey`], thus you should already
142 /// know how to spend it. No secret keys are provided as LDK was never given any key.
143 /// These may include outputs from a transaction punishing our counterparty or claiming an HTLC
144 /// on-chain using the payment preimage or after it has timed out.
146 /// [`get_shutdown_scriptpubkey`]: SignerProvider::get_shutdown_scriptpubkey
147 /// [`get_destination_script`]: SignerProvider::get_shutdown_scriptpubkey
149 /// The outpoint which is spendable.
151 /// The output which is referenced by the given outpoint.
154 /// An output to a P2WSH script which can be spent with a single signature after an `OP_CSV`
157 /// The witness in the spending input should be:
159 /// <BIP 143 signature> <empty vector> (MINIMALIF standard rule) <provided witnessScript>
162 /// Note that the `nSequence` field in the spending input must be set to
163 /// [`DelayedPaymentOutputDescriptor::to_self_delay`] (which means the transaction is not
164 /// broadcastable until at least [`DelayedPaymentOutputDescriptor::to_self_delay`] blocks after
165 /// the outpoint confirms, see [BIP
166 /// 68](https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki)). Also note that LDK
167 /// won't generate a [`SpendableOutputDescriptor`] until the corresponding block height
170 /// These are generally the result of a "revocable" output to us, spendable only by us unless
171 /// it is an output from an old state which we broadcast (which should never happen).
173 /// To derive the delayed payment key which is used to sign this input, you must pass the
174 /// holder [`InMemorySigner::delayed_payment_base_key`] (i.e., the private key which corresponds to the
175 /// [`ChannelPublicKeys::delayed_payment_basepoint`] in [`ChannelSigner::pubkeys`]) and the provided
176 /// [`DelayedPaymentOutputDescriptor::per_commitment_point`] to [`chan_utils::derive_private_key`]. The public key can be
177 /// generated without the secret key using [`chan_utils::derive_public_key`] and only the
178 /// [`ChannelPublicKeys::delayed_payment_basepoint`] which appears in [`ChannelSigner::pubkeys`].
180 /// To derive the [`DelayedPaymentOutputDescriptor::revocation_pubkey`] provided here (which is
181 /// used in the witness script generation), you must pass the counterparty
182 /// [`ChannelPublicKeys::revocation_basepoint`] (which appears in the call to
183 /// [`ChannelSigner::provide_channel_parameters`]) and the provided
184 /// [`DelayedPaymentOutputDescriptor::per_commitment_point`] to
185 /// [`chan_utils::derive_public_revocation_key`].
187 /// The witness script which is hashed and included in the output `script_pubkey` may be
188 /// regenerated by passing the [`DelayedPaymentOutputDescriptor::revocation_pubkey`] (derived
189 /// as explained above), our delayed payment pubkey (derived as explained above), and the
190 /// [`DelayedPaymentOutputDescriptor::to_self_delay`] contained here to
191 /// [`chan_utils::get_revokeable_redeemscript`].
192 DelayedPaymentOutput(DelayedPaymentOutputDescriptor),
193 /// An output to a P2WPKH, spendable exclusively by our payment key (i.e., the private key
194 /// which corresponds to the `payment_point` in [`ChannelSigner::pubkeys`]). The witness
195 /// in the spending input is, thus, simply:
197 /// <BIP 143 signature> <payment key>
200 /// These are generally the result of our counterparty having broadcast the current state,
201 /// allowing us to claim the non-HTLC-encumbered outputs immediately.
202 StaticPaymentOutput(StaticPaymentOutputDescriptor),
205 impl_writeable_tlv_based_enum!(SpendableOutputDescriptor,
206 (0, StaticOutput) => {
207 (0, outpoint, required),
208 (2, output, required),
211 (1, DelayedPaymentOutput),
212 (2, StaticPaymentOutput),
215 /// A trait to handle Lightning channel key material without concretizing the channel type or
216 /// the signature mechanism.
217 pub trait ChannelSigner {
218 /// Gets the per-commitment point for a specific commitment number
220 /// Note that the commitment number starts at `(1 << 48) - 1` and counts backwards.
221 fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey;
223 /// Gets the commitment secret for a specific commitment number as part of the revocation process
225 /// An external signer implementation should error here if the commitment was already signed
226 /// and should refuse to sign it in the future.
228 /// May be called more than once for the same index.
230 /// Note that the commitment number starts at `(1 << 48) - 1` and counts backwards.
231 // TODO: return a Result so we can signal a validation error
232 fn release_commitment_secret(&self, idx: u64) -> [u8; 32];
234 /// Validate the counterparty's signatures on the holder commitment transaction and HTLCs.
236 /// This is required in order for the signer to make sure that releasing a commitment
237 /// secret won't leave us without a broadcastable holder transaction.
238 /// Policy checks should be implemented in this function, including checking the amount
239 /// sent to us and checking the HTLCs.
241 /// The preimages of outgoing HTLCs that were fulfilled since the last commitment are provided.
242 /// A validating signer should ensure that an HTLC output is removed only when the matching
243 /// preimage is provided, or when the value to holder is restored.
245 /// Note that all the relevant preimages will be provided, but there may also be additional
246 /// irrelevant or duplicate preimages.
247 fn validate_holder_commitment(&self, holder_tx: &HolderCommitmentTransaction,
248 preimages: Vec<PaymentPreimage>) -> Result<(), ()>;
250 /// Returns the holder's channel public keys and basepoints.
251 fn pubkeys(&self) -> &ChannelPublicKeys;
253 /// Returns an arbitrary identifier describing the set of keys which are provided back to you in
254 /// some [`SpendableOutputDescriptor`] types. This should be sufficient to identify this
255 /// [`EcdsaChannelSigner`] object uniquely and lookup or re-derive its keys.
256 fn channel_keys_id(&self) -> [u8; 32];
258 /// Set the counterparty static channel data, including basepoints,
259 /// `counterparty_selected`/`holder_selected_contest_delay` and funding outpoint.
261 /// This data is static, and will never change for a channel once set. For a given [`ChannelSigner`]
262 /// instance, LDK will call this method exactly once - either immediately after construction
263 /// (not including if done via [`SignerProvider::read_chan_signer`]) or when the funding
264 /// information has been generated.
266 /// channel_parameters.is_populated() MUST be true.
267 fn provide_channel_parameters(&mut self, channel_parameters: &ChannelTransactionParameters);
270 /// A trait to sign Lightning channel transactions as described in
271 /// [BOLT 3](https://github.com/lightning/bolts/blob/master/03-transactions.md).
273 /// Signing services could be implemented on a hardware wallet and should implement signing
274 /// policies in order to be secure. Please refer to the [VLS Policy
275 /// Controls](https://gitlab.com/lightning-signer/validating-lightning-signer/-/blob/main/docs/policy-controls.md)
276 /// for an example of such policies.
277 pub trait EcdsaChannelSigner: ChannelSigner {
278 /// Create a signature for a counterparty's commitment transaction and associated HTLC transactions.
280 /// Note that if signing fails or is rejected, the channel will be force-closed.
282 /// Policy checks should be implemented in this function, including checking the amount
283 /// sent to us and checking the HTLCs.
285 /// The preimages of outgoing HTLCs that were fulfilled since the last commitment are provided.
286 /// A validating signer should ensure that an HTLC output is removed only when the matching
287 /// preimage is provided, or when the value to holder is restored.
289 /// Note that all the relevant preimages will be provided, but there may also be additional
290 /// irrelevant or duplicate preimages.
292 // TODO: Document the things someone using this interface should enforce before signing.
293 fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction,
294 preimages: Vec<PaymentPreimage>, secp_ctx: &Secp256k1<secp256k1::All>
295 ) -> Result<(Signature, Vec<Signature>), ()>;
296 /// Validate the counterparty's revocation.
298 /// This is required in order for the signer to make sure that the state has moved
299 /// forward and it is safe to sign the next counterparty commitment.
300 fn validate_counterparty_revocation(&self, idx: u64, secret: &SecretKey) -> Result<(), ()>;
301 /// Creates a signature for a holder's commitment transaction and its claiming HTLC transactions.
303 /// This will be called
304 /// - with a non-revoked `commitment_tx`.
305 /// - with the latest `commitment_tx` when we initiate a force-close.
306 /// - with the previous `commitment_tx`, just to get claiming HTLC
307 /// signatures, if we are reacting to a [`ChannelMonitor`]
308 /// [replica](https://github.com/lightningdevkit/rust-lightning/blob/main/GLOSSARY.md#monitor-replicas)
309 /// that decided to broadcast before it had been updated to the latest `commitment_tx`.
311 /// This may be called multiple times for the same transaction.
313 /// An external signer implementation should check that the commitment has not been revoked.
315 /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
316 // TODO: Document the things someone using this interface should enforce before signing.
317 fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction,
318 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
319 /// Same as [`sign_holder_commitment_and_htlcs`], but exists only for tests to get access to
320 /// holder commitment transactions which will be broadcasted later, after the channel has moved
321 /// on to a newer state. Thus, needs its own method as [`sign_holder_commitment_and_htlcs`] may
322 /// enforce that we only ever get called once.
323 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
324 fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction,
325 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()>;
326 /// Create a signature for the given input in a transaction spending an HTLC transaction output
327 /// or a commitment transaction `to_local` output when our counterparty broadcasts an old state.
329 /// A justice transaction may claim multiple outputs at the same time if timelocks are
330 /// similar, but only a signature for the input at index `input` should be signed for here.
331 /// It may be called multiple times for same output(s) if a fee-bump is needed with regards
332 /// to an upcoming timelock expiration.
334 /// Amount is value of the output spent by this input, committed to in the BIP 143 signature.
336 /// `per_commitment_key` is revocation secret which was provided by our counterparty when they
337 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
338 /// not allow the spending of any funds by itself (you need our holder `revocation_secret` to do
340 fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64,
341 per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>
342 ) -> Result<Signature, ()>;
343 /// Create a signature for the given input in a transaction spending a commitment transaction
344 /// HTLC output when our counterparty broadcasts an old state.
346 /// A justice transaction may claim multiple outputs at the same time if timelocks are
347 /// similar, but only a signature for the input at index `input` should be signed for here.
348 /// It may be called multiple times for same output(s) if a fee-bump is needed with regards
349 /// to an upcoming timelock expiration.
351 /// `amount` is the value of the output spent by this input, committed to in the BIP 143
354 /// `per_commitment_key` is revocation secret which was provided by our counterparty when they
355 /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does
356 /// not allow the spending of any funds by itself (you need our holder revocation_secret to do
359 /// `htlc` holds HTLC elements (hash, timelock), thus changing the format of the witness script
360 /// (which is committed to in the BIP 143 signatures).
361 fn sign_justice_revoked_htlc(&self, justice_tx: &Transaction, input: usize, amount: u64,
362 per_commitment_key: &SecretKey, htlc: &HTLCOutputInCommitment,
363 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
365 /// Computes the signature for a commitment transaction's HTLC output used as an input within
366 /// `htlc_tx`, which spends the commitment transaction at index `input`. The signature returned
367 /// must be be computed using [`EcdsaSighashType::All`]. Note that this should only be used to
368 /// sign HTLC transactions from channels supporting anchor outputs after all additional
369 /// inputs/outputs have been added to the transaction.
371 /// [`EcdsaSighashType::All`]: bitcoin::blockdata::transaction::EcdsaSighashType::All
372 fn sign_holder_htlc_transaction(&self, htlc_tx: &Transaction, input: usize,
373 htlc_descriptor: &HTLCDescriptor, secp_ctx: &Secp256k1<secp256k1::All>
374 ) -> Result<Signature, ()>;
375 /// Create a signature for a claiming transaction for a HTLC output on a counterparty's commitment
376 /// transaction, either offered or received.
378 /// Such a transaction may claim multiples offered outputs at same time if we know the
379 /// preimage for each when we create it, but only the input at index `input` should be
380 /// signed for here. It may be called multiple times for same output(s) if a fee-bump is
381 /// needed with regards to an upcoming timelock expiration.
383 /// `witness_script` is either an offered or received script as defined in BOLT3 for HTLC
386 /// `amount` is value of the output spent by this input, committed to in the BIP 143 signature.
388 /// `per_commitment_point` is the dynamic point corresponding to the channel state
389 /// detected onchain. It has been generated by our counterparty and is used to derive
390 /// channel state keys, which are then included in the witness script and committed to in the
391 /// BIP 143 signature.
392 fn sign_counterparty_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64,
393 per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment,
394 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
395 /// Create a signature for a (proposed) closing transaction.
397 /// Note that, due to rounding, there may be one "missing" satoshi, and either party may have
398 /// chosen to forgo their output as dust.
399 fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction,
400 secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()>;
401 /// Computes the signature for a commitment transaction's anchor output used as an
402 /// input within `anchor_tx`, which spends the commitment transaction, at index `input`.
403 fn sign_holder_anchor_input(
404 &self, anchor_tx: &Transaction, input: usize, secp_ctx: &Secp256k1<secp256k1::All>,
405 ) -> Result<Signature, ()>;
406 /// Signs a channel announcement message with our funding key proving it comes from one of the
407 /// channel participants.
409 /// Channel announcements also require a signature from each node's network key. Our node
410 /// signature is computed through [`NodeSigner::sign_gossip_message`].
412 /// Note that if this fails or is rejected, the channel will not be publicly announced and
413 /// our counterparty may (though likely will not) close the channel on us for violating the
415 fn sign_channel_announcement_with_funding_key(
416 &self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>
417 ) -> Result<Signature, ()>;
420 /// A writeable signer.
422 /// There will always be two instances of a signer per channel, one occupied by the
423 /// [`ChannelManager`] and another by the channel's [`ChannelMonitor`].
425 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
426 /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
427 pub trait WriteableEcdsaChannelSigner: EcdsaChannelSigner + Writeable {}
429 /// Specifies the recipient of an invoice.
431 /// This indicates to [`NodeSigner::sign_invoice`] what node secret key should be used to sign
434 /// The invoice should be signed with the local node secret key.
436 /// The invoice should be signed with the phantom node secret key. This secret key must be the
437 /// same for all nodes participating in the [phantom node payment].
439 /// [phantom node payment]: PhantomKeysManager
443 /// A trait that describes a source of entropy.
444 pub trait EntropySource {
445 /// Gets a unique, cryptographically-secure, random 32-byte value. This method must return a
446 /// different value each time it is called.
447 fn get_secure_random_bytes(&self) -> [u8; 32];
450 /// A trait that can handle cryptographic operations at the scope level of a node.
451 pub trait NodeSigner {
452 /// Get secret key material as bytes for use in encrypting and decrypting inbound payment data.
454 /// If the implementor of this trait supports [phantom node payments], then every node that is
455 /// intended to be included in the phantom invoice route hints must return the same value from
457 // This is because LDK avoids storing inbound payment data by encrypting payment data in the
458 // payment hash and/or payment secret, therefore for a payment to be receivable by multiple
459 // nodes, they must share the key that encrypts this payment data.
461 /// This method must return the same value each time it is called.
463 /// [phantom node payments]: PhantomKeysManager
464 fn get_inbound_payment_key_material(&self) -> KeyMaterial;
466 /// Get node id based on the provided [`Recipient`].
468 /// This method must return the same value each time it is called with a given [`Recipient`]
471 /// Errors if the [`Recipient`] variant is not supported by the implementation.
472 fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()>;
474 /// Gets the ECDH shared secret of our node secret and `other_key`, multiplying by `tweak` if
475 /// one is provided. Note that this tweak can be applied to `other_key` instead of our node
476 /// secret, though this is less efficient.
478 /// Note that if this fails while attempting to forward an HTLC, LDK will panic. The error
479 /// should be resolved to allow LDK to resume forwarding HTLCs.
481 /// Errors if the [`Recipient`] variant is not supported by the implementation.
482 fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()>;
486 /// By parameterizing by the raw invoice bytes instead of the hash, we allow implementors of
487 /// this trait to parse the invoice and make sure they're signing what they expect, rather than
488 /// blindly signing the hash.
490 /// The `hrp_bytes` are ASCII bytes, while the `invoice_data` is base32.
492 /// The secret key used to sign the invoice is dependent on the [`Recipient`].
494 /// Errors if the [`Recipient`] variant is not supported by the implementation.
495 fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient) -> Result<RecoverableSignature, ()>;
497 /// Sign a gossip message.
499 /// Note that if this fails, LDK may panic and the message will not be broadcast to the network
500 /// or a possible channel counterparty. If LDK panics, the error should be resolved to allow the
501 /// message to be broadcast, as otherwise it may prevent one from receiving funds over the
502 /// corresponding channel.
503 fn sign_gossip_message(&self, msg: UnsignedGossipMessage) -> Result<Signature, ()>;
506 /// A trait that can return signer instances for individual channels.
507 pub trait SignerProvider {
508 /// A type which implements [`WriteableEcdsaChannelSigner`] which will be returned by [`Self::derive_channel_signer`].
509 type Signer : WriteableEcdsaChannelSigner;
511 /// Generates a unique `channel_keys_id` that can be used to obtain a [`Self::Signer`] through
512 /// [`SignerProvider::derive_channel_signer`]. The `user_channel_id` is provided to allow
513 /// implementations of [`SignerProvider`] to maintain a mapping between itself and the generated
514 /// `channel_keys_id`.
516 /// This method must return a different value each time it is called.
517 fn generate_channel_keys_id(&self, inbound: bool, channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32];
519 /// Derives the private key material backing a `Signer`.
521 /// To derive a new `Signer`, a fresh `channel_keys_id` should be obtained through
522 /// [`SignerProvider::generate_channel_keys_id`]. Otherwise, an existing `Signer` can be
523 /// re-derived from its `channel_keys_id`, which can be obtained through its trait method
524 /// [`ChannelSigner::channel_keys_id`].
525 fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::Signer;
527 /// Reads a [`Signer`] for this [`SignerProvider`] from the given input stream.
528 /// This is only called during deserialization of other objects which contain
529 /// [`WriteableEcdsaChannelSigner`]-implementing objects (i.e., [`ChannelMonitor`]s and [`ChannelManager`]s).
530 /// The bytes are exactly those which `<Self::Signer as Writeable>::write()` writes, and
531 /// contain no versioning scheme. You may wish to include your own version prefix and ensure
532 /// you've read all of the provided bytes to ensure no corruption occurred.
534 /// This method is slowly being phased out -- it will only be called when reading objects
535 /// written by LDK versions prior to 0.0.113.
537 /// [`Signer`]: Self::Signer
538 /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
539 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
540 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError>;
542 /// Get a script pubkey which we send funds to when claiming on-chain contestable outputs.
544 /// This method should return a different value each time it is called, to avoid linking
545 /// on-chain funds across channels as controlled to the same user.
546 fn get_destination_script(&self) -> Script;
548 /// Get a script pubkey which we will send funds to when closing a channel.
550 /// This method should return a different value each time it is called, to avoid linking
551 /// on-chain funds across channels as controlled to the same user.
552 fn get_shutdown_scriptpubkey(&self) -> ShutdownScript;
556 /// A simple implementation of [`WriteableEcdsaChannelSigner`] that just keeps the private keys in memory.
558 /// This implementation performs no policy checks and is insufficient by itself as
559 /// a secure external signer.
560 pub struct InMemorySigner {
561 /// Holder secret key in the 2-of-2 multisig script of a channel. This key also backs the
562 /// holder's anchor output in a commitment transaction, if one is present.
563 pub funding_key: SecretKey,
564 /// Holder secret key for blinded revocation pubkey.
565 pub revocation_base_key: SecretKey,
566 /// Holder secret key used for our balance in counterparty-broadcasted commitment transactions.
567 pub payment_key: SecretKey,
568 /// Holder secret key used in an HTLC transaction.
569 pub delayed_payment_base_key: SecretKey,
570 /// Holder HTLC secret key used in commitment transaction HTLC outputs.
571 pub htlc_base_key: SecretKey,
573 pub commitment_seed: [u8; 32],
574 /// Holder public keys and basepoints.
575 pub(crate) holder_channel_pubkeys: ChannelPublicKeys,
576 /// Counterparty public keys and counterparty/holder `selected_contest_delay`, populated on channel acceptance.
577 channel_parameters: Option<ChannelTransactionParameters>,
578 /// The total value of this channel.
579 channel_value_satoshis: u64,
580 /// Key derivation parameters.
581 channel_keys_id: [u8; 32],
584 impl InMemorySigner {
585 /// Creates a new [`InMemorySigner`].
586 pub fn new<C: Signing>(
587 secp_ctx: &Secp256k1<C>,
588 funding_key: SecretKey,
589 revocation_base_key: SecretKey,
590 payment_key: SecretKey,
591 delayed_payment_base_key: SecretKey,
592 htlc_base_key: SecretKey,
593 commitment_seed: [u8; 32],
594 channel_value_satoshis: u64,
595 channel_keys_id: [u8; 32],
596 ) -> InMemorySigner {
597 let holder_channel_pubkeys =
598 InMemorySigner::make_holder_keys(secp_ctx, &funding_key, &revocation_base_key,
599 &payment_key, &delayed_payment_base_key,
605 delayed_payment_base_key,
608 channel_value_satoshis,
609 holder_channel_pubkeys,
610 channel_parameters: None,
615 fn make_holder_keys<C: Signing>(secp_ctx: &Secp256k1<C>,
616 funding_key: &SecretKey,
617 revocation_base_key: &SecretKey,
618 payment_key: &SecretKey,
619 delayed_payment_base_key: &SecretKey,
620 htlc_base_key: &SecretKey) -> ChannelPublicKeys {
621 let from_secret = |s: &SecretKey| PublicKey::from_secret_key(secp_ctx, s);
623 funding_pubkey: from_secret(&funding_key),
624 revocation_basepoint: from_secret(&revocation_base_key),
625 payment_point: from_secret(&payment_key),
626 delayed_payment_basepoint: from_secret(&delayed_payment_base_key),
627 htlc_basepoint: from_secret(&htlc_base_key),
631 /// Returns the counterparty's pubkeys.
633 /// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before.
634 pub fn counterparty_pubkeys(&self) -> &ChannelPublicKeys { &self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().pubkeys }
635 /// Returns the `contest_delay` value specified by our counterparty and applied on holder-broadcastable
636 /// transactions, i.e., the amount of time that we have to wait to recover our funds if we
637 /// broadcast a transaction.
639 /// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before.
640 pub fn counterparty_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().selected_contest_delay }
641 /// Returns the `contest_delay` value specified by us and applied on transactions broadcastable
642 /// by our counterparty, i.e., the amount of time that they have to wait to recover their funds
643 /// if they broadcast a transaction.
645 /// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before.
646 pub fn holder_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().holder_selected_contest_delay }
647 /// Returns whether the holder is the initiator.
649 /// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before.
650 pub fn is_outbound(&self) -> bool { self.get_channel_parameters().is_outbound_from_holder }
653 /// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before.
654 pub fn funding_outpoint(&self) -> &OutPoint { self.get_channel_parameters().funding_outpoint.as_ref().unwrap() }
655 /// Returns a [`ChannelTransactionParameters`] for this channel, to be used when verifying or
656 /// building transactions.
658 /// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before.
659 pub fn get_channel_parameters(&self) -> &ChannelTransactionParameters {
660 self.channel_parameters.as_ref().unwrap()
662 /// Returns whether anchors should be used.
664 /// Will panic if [`ChannelSigner::provide_channel_parameters`] has not been called before.
665 pub fn opt_anchors(&self) -> bool {
666 self.get_channel_parameters().opt_anchors.is_some()
668 /// Sign the single input of `spend_tx` at index `input_idx`, which spends the output described
669 /// by `descriptor`, returning the witness stack for the input.
671 /// Returns an error if the input at `input_idx` does not exist, has a non-empty `script_sig`,
672 /// is not spending the outpoint described by [`descriptor.outpoint`],
673 /// or if an output descriptor `script_pubkey` does not match the one we can spend.
675 /// [`descriptor.outpoint`]: StaticPaymentOutputDescriptor::outpoint
676 pub fn sign_counterparty_payment_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &StaticPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Vec<Vec<u8>>, ()> {
677 // TODO: We really should be taking the SigHashCache as a parameter here instead of
678 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
679 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
680 // bindings updates to support SigHashCache objects).
681 if spend_tx.input.len() <= input_idx { return Err(()); }
682 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
683 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
685 let remotepubkey = self.pubkeys().payment_point;
686 let witness_script = bitcoin::Address::p2pkh(&::bitcoin::PublicKey{compressed: true, inner: remotepubkey}, Network::Testnet).script_pubkey();
687 let sighash = hash_to_message!(&sighash::SighashCache::new(spend_tx).segwit_signature_hash(input_idx, &witness_script, descriptor.output.value, EcdsaSighashType::All).unwrap()[..]);
688 let remotesig = sign(secp_ctx, &sighash, &self.payment_key);
689 let payment_script = bitcoin::Address::p2wpkh(&::bitcoin::PublicKey{compressed: true, inner: remotepubkey}, Network::Bitcoin).unwrap().script_pubkey();
691 if payment_script != descriptor.output.script_pubkey { return Err(()); }
693 let mut witness = Vec::with_capacity(2);
694 witness.push(remotesig.serialize_der().to_vec());
695 witness[0].push(EcdsaSighashType::All as u8);
696 witness.push(remotepubkey.serialize().to_vec());
700 /// Sign the single input of `spend_tx` at index `input_idx` which spends the output
701 /// described by `descriptor`, returning the witness stack for the input.
703 /// Returns an error if the input at `input_idx` does not exist, has a non-empty `script_sig`,
704 /// is not spending the outpoint described by [`descriptor.outpoint`], does not have a
705 /// sequence set to [`descriptor.to_self_delay`], or if an output descriptor
706 /// `script_pubkey` does not match the one we can spend.
708 /// [`descriptor.outpoint`]: DelayedPaymentOutputDescriptor::outpoint
709 /// [`descriptor.to_self_delay`]: DelayedPaymentOutputDescriptor::to_self_delay
710 pub fn sign_dynamic_p2wsh_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &DelayedPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Vec<Vec<u8>>, ()> {
711 // TODO: We really should be taking the SigHashCache as a parameter here instead of
712 // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
713 // so that we can check them. This requires upstream rust-bitcoin changes (as well as
714 // bindings updates to support SigHashCache objects).
715 if spend_tx.input.len() <= input_idx { return Err(()); }
716 if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
717 if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
718 if spend_tx.input[input_idx].sequence.0 != descriptor.to_self_delay as u32 { return Err(()); }
720 let delayed_payment_key = chan_utils::derive_private_key(&secp_ctx, &descriptor.per_commitment_point, &self.delayed_payment_base_key);
721 let delayed_payment_pubkey = PublicKey::from_secret_key(&secp_ctx, &delayed_payment_key);
722 let witness_script = chan_utils::get_revokeable_redeemscript(&descriptor.revocation_pubkey, descriptor.to_self_delay, &delayed_payment_pubkey);
723 let sighash = hash_to_message!(&sighash::SighashCache::new(spend_tx).segwit_signature_hash(input_idx, &witness_script, descriptor.output.value, EcdsaSighashType::All).unwrap()[..]);
724 let local_delayedsig = sign(secp_ctx, &sighash, &delayed_payment_key);
725 let payment_script = bitcoin::Address::p2wsh(&witness_script, Network::Bitcoin).script_pubkey();
727 if descriptor.output.script_pubkey != payment_script { return Err(()); }
729 let mut witness = Vec::with_capacity(3);
730 witness.push(local_delayedsig.serialize_der().to_vec());
731 witness[0].push(EcdsaSighashType::All as u8);
732 witness.push(vec!()); //MINIMALIF
733 witness.push(witness_script.clone().into_bytes());
738 impl ChannelSigner for InMemorySigner {
739 fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey {
740 let commitment_secret = SecretKey::from_slice(&chan_utils::build_commitment_secret(&self.commitment_seed, idx)).unwrap();
741 PublicKey::from_secret_key(secp_ctx, &commitment_secret)
744 fn release_commitment_secret(&self, idx: u64) -> [u8; 32] {
745 chan_utils::build_commitment_secret(&self.commitment_seed, idx)
748 fn validate_holder_commitment(&self, _holder_tx: &HolderCommitmentTransaction, _preimages: Vec<PaymentPreimage>) -> Result<(), ()> {
752 fn pubkeys(&self) -> &ChannelPublicKeys { &self.holder_channel_pubkeys }
754 fn channel_keys_id(&self) -> [u8; 32] { self.channel_keys_id }
756 fn provide_channel_parameters(&mut self, channel_parameters: &ChannelTransactionParameters) {
757 assert!(self.channel_parameters.is_none() || self.channel_parameters.as_ref().unwrap() == channel_parameters);
758 if self.channel_parameters.is_some() {
759 // The channel parameters were already set and they match, return early.
762 assert!(channel_parameters.is_populated(), "Channel parameters must be fully populated");
763 self.channel_parameters = Some(channel_parameters.clone());
767 impl EcdsaChannelSigner for InMemorySigner {
768 fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, _preimages: Vec<PaymentPreimage>, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
769 let trusted_tx = commitment_tx.trust();
770 let keys = trusted_tx.keys();
772 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
773 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
775 let built_tx = trusted_tx.built_transaction();
776 let commitment_sig = built_tx.sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx);
777 let commitment_txid = built_tx.txid;
779 let mut htlc_sigs = Vec::with_capacity(commitment_tx.htlcs().len());
780 for htlc in commitment_tx.htlcs() {
781 let channel_parameters = self.get_channel_parameters();
782 let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_tx.feerate_per_kw(), self.holder_selected_contest_delay(), htlc, self.opt_anchors(), channel_parameters.opt_non_zero_fee_anchors.is_some(), &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
783 let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, self.opt_anchors(), &keys);
784 let htlc_sighashtype = if self.opt_anchors() { EcdsaSighashType::SinglePlusAnyoneCanPay } else { EcdsaSighashType::All };
785 let htlc_sighash = hash_to_message!(&sighash::SighashCache::new(&htlc_tx).segwit_signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, htlc_sighashtype).unwrap()[..]);
786 let holder_htlc_key = chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key);
787 htlc_sigs.push(sign(secp_ctx, &htlc_sighash, &holder_htlc_key));
790 Ok((commitment_sig, htlc_sigs))
793 fn validate_counterparty_revocation(&self, _idx: u64, _secret: &SecretKey) -> Result<(), ()> {
797 fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
798 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
799 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
800 let trusted_tx = commitment_tx.trust();
801 let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
802 let channel_parameters = self.get_channel_parameters();
803 let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
807 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
808 fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
809 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
810 let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
811 let trusted_tx = commitment_tx.trust();
812 let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
813 let channel_parameters = self.get_channel_parameters();
814 let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
818 fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
819 let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key);
820 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
821 let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint);
822 let witness_script = {
823 let counterparty_delayedpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().delayed_payment_basepoint);
824 chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.holder_selected_contest_delay(), &counterparty_delayedpubkey)
826 let mut sighash_parts = sighash::SighashCache::new(justice_tx);
827 let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
828 return Ok(sign(secp_ctx, &sighash, &revocation_key))
831 fn sign_justice_revoked_htlc(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
832 let revocation_key = chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key);
833 let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key);
834 let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint);
835 let witness_script = {
836 let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint);
837 let holder_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint);
838 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, self.opt_anchors(), &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey)
840 let mut sighash_parts = sighash::SighashCache::new(justice_tx);
841 let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
842 return Ok(sign(secp_ctx, &sighash, &revocation_key))
846 fn sign_holder_htlc_transaction(
847 &self, htlc_tx: &Transaction, input: usize, htlc_descriptor: &HTLCDescriptor,
848 secp_ctx: &Secp256k1<secp256k1::All>
849 ) -> Result<Signature, ()> {
850 let per_commitment_point = self.get_per_commitment_point(
851 htlc_descriptor.per_commitment_number, &secp_ctx
853 let witness_script = htlc_descriptor.witness_script(&per_commitment_point, secp_ctx);
854 let sighash = &sighash::SighashCache::new(&*htlc_tx).segwit_signature_hash(
855 input, &witness_script, htlc_descriptor.htlc.amount_msat / 1000, EcdsaSighashType::All
857 let our_htlc_private_key = chan_utils::derive_private_key(
858 &secp_ctx, &per_commitment_point, &self.htlc_base_key
860 Ok(sign(&secp_ctx, &hash_to_message!(sighash), &our_htlc_private_key))
863 fn sign_counterparty_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
864 let htlc_key = chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key);
865 let revocation_pubkey = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint);
866 let counterparty_htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint);
867 let htlcpubkey = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint);
868 let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, self.opt_anchors(), &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey);
869 let mut sighash_parts = sighash::SighashCache::new(htlc_tx);
870 let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
871 Ok(sign(secp_ctx, &sighash, &htlc_key))
874 fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
875 let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
876 let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
877 Ok(closing_tx.trust().sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx))
880 fn sign_holder_anchor_input(
881 &self, anchor_tx: &Transaction, input: usize, secp_ctx: &Secp256k1<secp256k1::All>,
882 ) -> Result<Signature, ()> {
883 let witness_script = chan_utils::get_anchor_redeemscript(&self.holder_channel_pubkeys.funding_pubkey);
884 let sighash = sighash::SighashCache::new(&*anchor_tx).segwit_signature_hash(
885 input, &witness_script, ANCHOR_OUTPUT_VALUE_SATOSHI, EcdsaSighashType::All,
887 Ok(sign(secp_ctx, &hash_to_message!(&sighash[..]), &self.funding_key))
890 fn sign_channel_announcement_with_funding_key(
891 &self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>
892 ) -> Result<Signature, ()> {
893 let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
894 Ok(sign(secp_ctx, &msghash, &self.funding_key))
898 const SERIALIZATION_VERSION: u8 = 1;
900 const MIN_SERIALIZATION_VERSION: u8 = 1;
902 impl WriteableEcdsaChannelSigner for InMemorySigner {}
904 impl Writeable for InMemorySigner {
905 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
906 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
908 self.funding_key.write(writer)?;
909 self.revocation_base_key.write(writer)?;
910 self.payment_key.write(writer)?;
911 self.delayed_payment_base_key.write(writer)?;
912 self.htlc_base_key.write(writer)?;
913 self.commitment_seed.write(writer)?;
914 self.channel_parameters.write(writer)?;
915 self.channel_value_satoshis.write(writer)?;
916 self.channel_keys_id.write(writer)?;
918 write_tlv_fields!(writer, {});
924 impl Readable for InMemorySigner {
925 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
926 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
928 let funding_key = Readable::read(reader)?;
929 let revocation_base_key = Readable::read(reader)?;
930 let payment_key = Readable::read(reader)?;
931 let delayed_payment_base_key = Readable::read(reader)?;
932 let htlc_base_key = Readable::read(reader)?;
933 let commitment_seed = Readable::read(reader)?;
934 let counterparty_channel_data = Readable::read(reader)?;
935 let channel_value_satoshis = Readable::read(reader)?;
936 let secp_ctx = Secp256k1::signing_only();
937 let holder_channel_pubkeys =
938 InMemorySigner::make_holder_keys(&secp_ctx, &funding_key, &revocation_base_key,
939 &payment_key, &delayed_payment_base_key, &htlc_base_key);
940 let keys_id = Readable::read(reader)?;
942 read_tlv_fields!(reader, {});
948 delayed_payment_base_key,
951 channel_value_satoshis,
952 holder_channel_pubkeys,
953 channel_parameters: counterparty_channel_data,
954 channel_keys_id: keys_id,
959 /// Simple implementation of [`EntropySource`], [`NodeSigner`], and [`SignerProvider`] that takes a
960 /// 32-byte seed for use as a BIP 32 extended key and derives keys from that.
962 /// Your `node_id` is seed/0'.
963 /// Unilateral closes may use seed/1'.
964 /// Cooperative closes may use seed/2'.
965 /// The two close keys may be needed to claim on-chain funds!
967 /// This struct cannot be used for nodes that wish to support receiving phantom payments;
968 /// [`PhantomKeysManager`] must be used instead.
970 /// Note that switching between this struct and [`PhantomKeysManager`] will invalidate any
971 /// previously issued invoices and attempts to pay previous invoices will fail.
972 pub struct KeysManager {
973 secp_ctx: Secp256k1<secp256k1::All>,
974 node_secret: SecretKey,
976 inbound_payment_key: KeyMaterial,
977 destination_script: Script,
978 shutdown_pubkey: PublicKey,
979 channel_master_key: ExtendedPrivKey,
980 channel_child_index: AtomicUsize,
982 rand_bytes_master_key: ExtendedPrivKey,
983 rand_bytes_child_index: AtomicUsize,
984 rand_bytes_unique_start: Sha256State,
987 starting_time_secs: u64,
988 starting_time_nanos: u32,
992 /// Constructs a [`KeysManager`] from a 32-byte seed. If the seed is in some way biased (e.g.,
993 /// your CSRNG is busted) this may panic (but more importantly, you will possibly lose funds).
994 /// `starting_time` isn't strictly required to actually be a time, but it must absolutely,
995 /// without a doubt, be unique to this instance. ie if you start multiple times with the same
996 /// `seed`, `starting_time` must be unique to each run. Thus, the easiest way to achieve this
997 /// is to simply use the current time (with very high precision).
999 /// The `seed` MUST be backed up safely prior to use so that the keys can be re-created, however,
1000 /// obviously, `starting_time` should be unique every time you reload the library - it is only
1001 /// used to generate new ephemeral key data (which will be stored by the individual channel if
1004 /// Note that the seed is required to recover certain on-chain funds independent of
1005 /// [`ChannelMonitor`] data, though a current copy of [`ChannelMonitor`] data is also required
1006 /// for any channel, and some on-chain during-closing funds.
1008 /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
1009 pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32) -> Self {
1010 let secp_ctx = Secp256k1::new();
1011 // Note that when we aren't serializing the key, network doesn't matter
1012 match ExtendedPrivKey::new_master(Network::Testnet, seed) {
1014 let node_secret = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(0).unwrap()).expect("Your RNG is busted").private_key;
1015 let node_id = PublicKey::from_secret_key(&secp_ctx, &node_secret);
1016 let destination_script = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(1).unwrap()) {
1017 Ok(destination_key) => {
1018 let wpubkey_hash = WPubkeyHash::hash(&ExtendedPubKey::from_priv(&secp_ctx, &destination_key).to_pub().to_bytes());
1019 Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
1020 .push_slice(&wpubkey_hash.into_inner())
1023 Err(_) => panic!("Your RNG is busted"),
1025 let shutdown_pubkey = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(2).unwrap()) {
1026 Ok(shutdown_key) => ExtendedPubKey::from_priv(&secp_ctx, &shutdown_key).public_key,
1027 Err(_) => panic!("Your RNG is busted"),
1029 let channel_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(3).unwrap()).expect("Your RNG is busted");
1030 let rand_bytes_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(4).unwrap()).expect("Your RNG is busted");
1031 let inbound_payment_key: SecretKey = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(5).unwrap()).expect("Your RNG is busted").private_key;
1032 let mut inbound_pmt_key_bytes = [0; 32];
1033 inbound_pmt_key_bytes.copy_from_slice(&inbound_payment_key[..]);
1035 let mut rand_bytes_unique_start = Sha256::engine();
1036 rand_bytes_unique_start.input(&starting_time_secs.to_be_bytes());
1037 rand_bytes_unique_start.input(&starting_time_nanos.to_be_bytes());
1038 rand_bytes_unique_start.input(seed);
1040 let mut res = KeysManager {
1044 inbound_payment_key: KeyMaterial(inbound_pmt_key_bytes),
1050 channel_child_index: AtomicUsize::new(0),
1052 rand_bytes_master_key,
1053 rand_bytes_child_index: AtomicUsize::new(0),
1054 rand_bytes_unique_start,
1058 starting_time_nanos,
1060 let secp_seed = res.get_secure_random_bytes();
1061 res.secp_ctx.seeded_randomize(&secp_seed);
1064 Err(_) => panic!("Your rng is busted"),
1067 /// Derive an old [`WriteableEcdsaChannelSigner`] containing per-channel secrets based on a key derivation parameters.
1068 pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemorySigner {
1069 let chan_id = u64::from_be_bytes(params[0..8].try_into().unwrap());
1070 let mut unique_start = Sha256::engine();
1071 unique_start.input(params);
1072 unique_start.input(&self.seed);
1074 // We only seriously intend to rely on the channel_master_key for true secure
1075 // entropy, everything else just ensures uniqueness. We rely on the unique_start (ie
1076 // starting_time provided in the constructor) to be unique.
1077 let child_privkey = self.channel_master_key.ckd_priv(&self.secp_ctx,
1078 ChildNumber::from_hardened_idx((chan_id as u32) % (1 << 31)).expect("key space exhausted")
1079 ).expect("Your RNG is busted");
1080 unique_start.input(&child_privkey.private_key[..]);
1082 let seed = Sha256::from_engine(unique_start).into_inner();
1084 let commitment_seed = {
1085 let mut sha = Sha256::engine();
1087 sha.input(&b"commitment seed"[..]);
1088 Sha256::from_engine(sha).into_inner()
1090 macro_rules! key_step {
1091 ($info: expr, $prev_key: expr) => {{
1092 let mut sha = Sha256::engine();
1094 sha.input(&$prev_key[..]);
1095 sha.input(&$info[..]);
1096 SecretKey::from_slice(&Sha256::from_engine(sha).into_inner()).expect("SHA-256 is busted")
1099 let funding_key = key_step!(b"funding key", commitment_seed);
1100 let revocation_base_key = key_step!(b"revocation base key", funding_key);
1101 let payment_key = key_step!(b"payment key", revocation_base_key);
1102 let delayed_payment_base_key = key_step!(b"delayed payment base key", payment_key);
1103 let htlc_base_key = key_step!(b"HTLC base key", delayed_payment_base_key);
1105 InMemorySigner::new(
1108 revocation_base_key,
1110 delayed_payment_base_key,
1113 channel_value_satoshis,
1118 /// Creates a [`Transaction`] which spends the given descriptors to the given outputs, plus an
1119 /// output to the given change destination (if sufficient change value remains). The
1120 /// transaction will have a feerate, at least, of the given value.
1122 /// Returns `Err(())` if the output value is greater than the input value minus required fee,
1123 /// if a descriptor was duplicated, or if an output descriptor `script_pubkey`
1124 /// does not match the one we can spend.
1126 /// We do not enforce that outputs meet the dust limit or that any output scripts are standard.
1128 /// May panic if the [`SpendableOutputDescriptor`]s were not generated by channels which used
1129 /// this [`KeysManager`] or one of the [`InMemorySigner`] created by this [`KeysManager`].
1130 pub fn spend_spendable_outputs<C: Signing>(&self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>, change_destination_script: Script, feerate_sat_per_1000_weight: u32, secp_ctx: &Secp256k1<C>) -> Result<Transaction, ()> {
1131 let mut input = Vec::new();
1132 let mut input_value = 0;
1133 let mut witness_weight = 0;
1134 let mut output_set = HashSet::with_capacity(descriptors.len());
1135 for outp in descriptors {
1137 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
1139 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
1140 script_sig: Script::new(),
1141 sequence: Sequence::ZERO,
1142 witness: Witness::new(),
1144 witness_weight += StaticPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
1145 input_value += descriptor.output.value;
1146 if !output_set.insert(descriptor.outpoint) { return Err(()); }
1148 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
1150 previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
1151 script_sig: Script::new(),
1152 sequence: Sequence(descriptor.to_self_delay as u32),
1153 witness: Witness::new(),
1155 witness_weight += DelayedPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
1156 input_value += descriptor.output.value;
1157 if !output_set.insert(descriptor.outpoint) { return Err(()); }
1159 SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
1161 previous_output: outpoint.into_bitcoin_outpoint(),
1162 script_sig: Script::new(),
1163 sequence: Sequence::ZERO,
1164 witness: Witness::new(),
1166 witness_weight += 1 + 73 + 34;
1167 input_value += output.value;
1168 if !output_set.insert(*outpoint) { return Err(()); }
1171 if input_value > MAX_VALUE_MSAT / 1000 { return Err(()); }
1173 let mut spend_tx = Transaction {
1175 lock_time: PackedLockTime(0),
1179 let expected_max_weight =
1180 transaction_utils::maybe_add_change_output(&mut spend_tx, input_value, witness_weight, feerate_sat_per_1000_weight, change_destination_script)?;
1182 let mut keys_cache: Option<(InMemorySigner, [u8; 32])> = None;
1183 let mut input_idx = 0;
1184 for outp in descriptors {
1186 SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
1187 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
1189 self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
1190 descriptor.channel_keys_id));
1192 spend_tx.input[input_idx].witness = Witness::from_vec(keys_cache.as_ref().unwrap().0.sign_counterparty_payment_input(&spend_tx, input_idx, &descriptor, &secp_ctx)?);
1194 SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
1195 if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
1197 self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
1198 descriptor.channel_keys_id));
1200 spend_tx.input[input_idx].witness = Witness::from_vec(keys_cache.as_ref().unwrap().0.sign_dynamic_p2wsh_input(&spend_tx, input_idx, &descriptor, &secp_ctx)?);
1202 SpendableOutputDescriptor::StaticOutput { ref output, .. } => {
1203 let derivation_idx = if output.script_pubkey == self.destination_script {
1209 // Note that when we aren't serializing the key, network doesn't matter
1210 match ExtendedPrivKey::new_master(Network::Testnet, &self.seed) {
1212 match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(derivation_idx).expect("key space exhausted")) {
1214 Err(_) => panic!("Your RNG is busted"),
1217 Err(_) => panic!("Your rng is busted"),
1220 let pubkey = ExtendedPubKey::from_priv(&secp_ctx, &secret).to_pub();
1221 if derivation_idx == 2 {
1222 assert_eq!(pubkey.inner, self.shutdown_pubkey);
1224 let witness_script = bitcoin::Address::p2pkh(&pubkey, Network::Testnet).script_pubkey();
1225 let payment_script = bitcoin::Address::p2wpkh(&pubkey, Network::Testnet).expect("uncompressed key found").script_pubkey();
1227 if payment_script != output.script_pubkey { return Err(()); };
1229 let sighash = hash_to_message!(&sighash::SighashCache::new(&spend_tx).segwit_signature_hash(input_idx, &witness_script, output.value, EcdsaSighashType::All).unwrap()[..]);
1230 let sig = sign(secp_ctx, &sighash, &secret.private_key);
1231 let mut sig_ser = sig.serialize_der().to_vec();
1232 sig_ser.push(EcdsaSighashType::All as u8);
1233 spend_tx.input[input_idx].witness.push(sig_ser);
1234 spend_tx.input[input_idx].witness.push(pubkey.inner.serialize().to_vec());
1240 debug_assert!(expected_max_weight >= spend_tx.weight());
1241 // Note that witnesses with a signature vary somewhat in size, so allow
1242 // `expected_max_weight` to overshoot by up to 3 bytes per input.
1243 debug_assert!(expected_max_weight <= spend_tx.weight() + descriptors.len() * 3);
1249 impl EntropySource for KeysManager {
1250 fn get_secure_random_bytes(&self) -> [u8; 32] {
1251 let mut sha = self.rand_bytes_unique_start.clone();
1253 let child_ix = self.rand_bytes_child_index.fetch_add(1, Ordering::AcqRel);
1254 let child_privkey = self.rand_bytes_master_key.ckd_priv(&self.secp_ctx, ChildNumber::from_hardened_idx(child_ix as u32).expect("key space exhausted")).expect("Your RNG is busted");
1255 sha.input(&child_privkey.private_key[..]);
1257 sha.input(b"Unique Secure Random Bytes Salt");
1258 Sha256::from_engine(sha).into_inner()
1262 impl NodeSigner for KeysManager {
1263 fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()> {
1265 Recipient::Node => Ok(self.node_id.clone()),
1266 Recipient::PhantomNode => Err(())
1270 fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()> {
1271 let mut node_secret = match recipient {
1272 Recipient::Node => Ok(self.node_secret.clone()),
1273 Recipient::PhantomNode => Err(())
1275 if let Some(tweak) = tweak {
1276 node_secret = node_secret.mul_tweak(tweak).map_err(|_| ())?;
1278 Ok(SharedSecret::new(other_key, &node_secret))
1281 fn get_inbound_payment_key_material(&self) -> KeyMaterial {
1282 self.inbound_payment_key.clone()
1285 fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient) -> Result<RecoverableSignature, ()> {
1286 let preimage = construct_invoice_preimage(&hrp_bytes, &invoice_data);
1287 let secret = match recipient {
1288 Recipient::Node => Ok(&self.node_secret),
1289 Recipient::PhantomNode => Err(())
1291 Ok(self.secp_ctx.sign_ecdsa_recoverable(&hash_to_message!(&Sha256::hash(&preimage)), secret))
1294 fn sign_gossip_message(&self, msg: UnsignedGossipMessage) -> Result<Signature, ()> {
1295 let msg_hash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
1296 Ok(sign(&self.secp_ctx, &msg_hash, &self.node_secret))
1300 impl SignerProvider for KeysManager {
1301 type Signer = InMemorySigner;
1303 fn generate_channel_keys_id(&self, _inbound: bool, _channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32] {
1304 let child_idx = self.channel_child_index.fetch_add(1, Ordering::AcqRel);
1305 // `child_idx` is the only thing guaranteed to make each channel unique without a restart
1306 // (though `user_channel_id` should help, depending on user behavior). If it manages to
1307 // roll over, we may generate duplicate keys for two different channels, which could result
1308 // in loss of funds. Because we only support 32-bit+ systems, assert that our `AtomicUsize`
1309 // doesn't reach `u32::MAX`.
1310 assert!(child_idx < core::u32::MAX as usize, "2^32 channels opened without restart");
1311 let mut id = [0; 32];
1312 id[0..4].copy_from_slice(&(child_idx as u32).to_be_bytes());
1313 id[4..8].copy_from_slice(&self.starting_time_nanos.to_be_bytes());
1314 id[8..16].copy_from_slice(&self.starting_time_secs.to_be_bytes());
1315 id[16..32].copy_from_slice(&user_channel_id.to_be_bytes());
1319 fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::Signer {
1320 self.derive_channel_keys(channel_value_satoshis, &channel_keys_id)
1323 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError> {
1324 InMemorySigner::read(&mut io::Cursor::new(reader))
1327 fn get_destination_script(&self) -> Script {
1328 self.destination_script.clone()
1331 fn get_shutdown_scriptpubkey(&self) -> ShutdownScript {
1332 ShutdownScript::new_p2wpkh_from_pubkey(self.shutdown_pubkey.clone())
1336 /// Similar to [`KeysManager`], but allows the node using this struct to receive phantom node
1339 /// A phantom node payment is a payment made to a phantom invoice, which is an invoice that can be
1340 /// paid to one of multiple nodes. This works because we encode the invoice route hints such that
1341 /// LDK will recognize an incoming payment as destined for a phantom node, and collect the payment
1342 /// itself without ever needing to forward to this fake node.
1344 /// Phantom node payments are useful for load balancing between multiple LDK nodes. They also
1345 /// provide some fault tolerance, because payers will automatically retry paying other provided
1346 /// nodes in the case that one node goes down.
1348 /// Note that multi-path payments are not supported in phantom invoices for security reasons.
1349 // In the hypothetical case that we did support MPP phantom payments, there would be no way for
1350 // nodes to know when the full payment has been received (and the preimage can be released) without
1351 // significantly compromising on our safety guarantees. I.e., if we expose the ability for the user
1352 // to tell LDK when the preimage can be released, we open ourselves to attacks where the preimage
1353 // is released too early.
1355 /// Switching between this struct and [`KeysManager`] will invalidate any previously issued
1356 /// invoices and attempts to pay previous invoices will fail.
1357 pub struct PhantomKeysManager {
1359 inbound_payment_key: KeyMaterial,
1360 phantom_secret: SecretKey,
1361 phantom_node_id: PublicKey,
1364 impl EntropySource for PhantomKeysManager {
1365 fn get_secure_random_bytes(&self) -> [u8; 32] {
1366 self.inner.get_secure_random_bytes()
1370 impl NodeSigner for PhantomKeysManager {
1371 fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()> {
1373 Recipient::Node => self.inner.get_node_id(Recipient::Node),
1374 Recipient::PhantomNode => Ok(self.phantom_node_id.clone()),
1378 fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()> {
1379 let mut node_secret = match recipient {
1380 Recipient::Node => self.inner.node_secret.clone(),
1381 Recipient::PhantomNode => self.phantom_secret.clone(),
1383 if let Some(tweak) = tweak {
1384 node_secret = node_secret.mul_tweak(tweak).map_err(|_| ())?;
1386 Ok(SharedSecret::new(other_key, &node_secret))
1389 fn get_inbound_payment_key_material(&self) -> KeyMaterial {
1390 self.inbound_payment_key.clone()
1393 fn sign_invoice(&self, hrp_bytes: &[u8], invoice_data: &[u5], recipient: Recipient) -> Result<RecoverableSignature, ()> {
1394 let preimage = construct_invoice_preimage(&hrp_bytes, &invoice_data);
1395 let secret = match recipient {
1396 Recipient::Node => &self.inner.node_secret,
1397 Recipient::PhantomNode => &self.phantom_secret,
1399 Ok(self.inner.secp_ctx.sign_ecdsa_recoverable(&hash_to_message!(&Sha256::hash(&preimage)), secret))
1402 fn sign_gossip_message(&self, msg: UnsignedGossipMessage) -> Result<Signature, ()> {
1403 self.inner.sign_gossip_message(msg)
1407 impl SignerProvider for PhantomKeysManager {
1408 type Signer = InMemorySigner;
1410 fn generate_channel_keys_id(&self, inbound: bool, channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32] {
1411 self.inner.generate_channel_keys_id(inbound, channel_value_satoshis, user_channel_id)
1414 fn derive_channel_signer(&self, channel_value_satoshis: u64, channel_keys_id: [u8; 32]) -> Self::Signer {
1415 self.inner.derive_channel_signer(channel_value_satoshis, channel_keys_id)
1418 fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError> {
1419 self.inner.read_chan_signer(reader)
1422 fn get_destination_script(&self) -> Script {
1423 self.inner.get_destination_script()
1426 fn get_shutdown_scriptpubkey(&self) -> ShutdownScript {
1427 self.inner.get_shutdown_scriptpubkey()
1431 impl PhantomKeysManager {
1432 /// Constructs a [`PhantomKeysManager`] given a 32-byte seed and an additional `cross_node_seed`
1433 /// that is shared across all nodes that intend to participate in [phantom node payments]
1436 /// See [`KeysManager::new`] for more information on `seed`, `starting_time_secs`, and
1437 /// `starting_time_nanos`.
1439 /// `cross_node_seed` must be the same across all phantom payment-receiving nodes and also the
1440 /// same across restarts, or else inbound payments may fail.
1442 /// [phantom node payments]: PhantomKeysManager
1443 pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32, cross_node_seed: &[u8; 32]) -> Self {
1444 let inner = KeysManager::new(seed, starting_time_secs, starting_time_nanos);
1445 let (inbound_key, phantom_key) = hkdf_extract_expand_twice(b"LDK Inbound and Phantom Payment Key Expansion", cross_node_seed);
1446 let phantom_secret = SecretKey::from_slice(&phantom_key).unwrap();
1447 let phantom_node_id = PublicKey::from_secret_key(&inner.secp_ctx, &phantom_secret);
1450 inbound_payment_key: KeyMaterial(inbound_key),
1456 /// See [`KeysManager::spend_spendable_outputs`] for documentation on this method.
1457 pub fn spend_spendable_outputs<C: Signing>(&self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>, change_destination_script: Script, feerate_sat_per_1000_weight: u32, secp_ctx: &Secp256k1<C>) -> Result<Transaction, ()> {
1458 self.inner.spend_spendable_outputs(descriptors, outputs, change_destination_script, feerate_sat_per_1000_weight, secp_ctx)
1461 /// See [`KeysManager::derive_channel_keys`] for documentation on this method.
1462 pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemorySigner {
1463 self.inner.derive_channel_keys(channel_value_satoshis, params)
1467 // Ensure that EcdsaChannelSigner can have a vtable
1470 let _signer: Box<dyn EcdsaChannelSigner>;